Spring unit for chair seat frames



Jung 27, 1933. n c. w. sTEELr-:L I, 1,915,390

` SPRING UNIT FOR CHAIR SEAT FRAMES Filed Feb. 1o, 193i' lVN QMMQWMM v Mig@ which with 'other similar units is a Fi ure 1.

CLARENCE w.

Patented June l2?', 1933 UNITED STAT csrosa'r'rs, oHUsE'rfrs,

s'rEELE, or nELnos'E, Nn -DAvID I. selezione ro- HEYwooD-waxnrmnn A conrona'rIoN or xassacnusa'r'rs Levine.' or wquissacomm, or sos'ron, nassa- BPBENG 'UNIT FOR CHAIR SEAT FBAIES Appunti@ sied february 1o, 19in. .sei-iai iro.

spring unit dapted to be secured in the frame of a seat. According to the inventiona spring unit is provided which inay be made chiefly of iron strap or other suitable metal, together with a suitable number ofv springs.

For a more complete understanding of the invention reference may be had to the disclosure thereof in the following description and on the drawing, of which,

Figure 1 is a plan view of a frame for a chair seat including an embodiment of the invention.

Figure 2 is a section-on the line 2-2'of This invention relates to a igure 3 is a fragmentary view similar to Figure 2 nshowing the movable parts in a d'zfferent position of operation.

Figure 4 is a section on the line 4--4 of- Ficrure 1.

rectangular frame for a chair seat is illustrated in Figure 1. This may consist of four side bars 10, 11, 12 and 13 supported `iy suitable legs 14 at the corners of the frame.

Between two opposite side bars such as 1()` and 12' are strung a suitable number of spring units, one such unit being illustrated in Figure 2. Each of these units may consist of a stiif strap 20., preforablycof relatively heavy metal stock. This stap is formed with a depressed lower portion 21, from 'which its end portions 22 'and 23 slope upwardly as shown. Horizonta-lly disposed above this strap is a flexible strap 24 the end portions of which are turned under as at 25 to lap under the end portions of the strap 20and to be secured thereto. tions 25 of the upper strap are preferably of .spring metal, so that when the central portion of the flexible strap 24 is depressed, as when a weight is put upon tbe chair seat, the resilient turned under end portions 25 of the flexible strap are adpted to yield. As shown on the drawing, the entire iexiblo strap 24 may consist of a single strip of thin, liexible steel, the end portions of which are turned under. Between the straps 20 and 24 are a number of compression springsi30, two

such springs being illustrated in the unit vvenient and suitable manner.

.The turned under por-V shown on the drawing. These springs may be of anyv type suitable for compressive resistance, the well known helical ty e beingA illustrated by way of example. "T e lower end of each .spring is suitably secured to the depressed portion of the strap 20, the upper end of each spring b eing secured to the flexible strap 24.

For the support of each unit,'a air of hangers 31 may be provided. Each anger 00 31 may consist of a piece of metal stock which may be similar to the stock used for the 'stiff strap, 20. Each shaped as shown in Figure 3, portion with one end a'wood screw or otherwise on the upper surface of one of the side members of the chair frame. The other end ortion 33 of the hanger extends rearwardy from the frame and downwardly to lap l0 the upwardly extending adjacent endof the stiff strap 20, to which it is secured. Thus the end portions of the three members 20, 24 and 31 may all be secured together in face to face4 relation, thev end portion of the flexible strap 24 being between vthe end portions ofthe members 20 and 31, as shown in Fig- These end portions may be secured a rivet 34 which passes them, or in an other con- T e end of the stiff member 20, resting upon the end of the strap 24, rovides eiicient support forv the turned un er portion 25. A This arrangement` also results metal strap being clamped between the heavier straps so that there is no danger of the thin metal being torn away from the rivet. When a weight is laced u on the flexible element 24 so as to the springs 30,l the turned under portions 25 are able to yield suiliciently to permit the necessary sag in the middle of the ilexible strap, as shown in Figure 3, without resultin in excessive stresses being imposed on the hangers 31. erably somewhat stiff and rigid, the resultant stresses on the hangers 31 are-chieiy downward rather than inward, so that there is,I little tendency on together as b through all o` hanger may be 32 horizontally disposed and adapt- $5 ed to be fastened by in the end portion of the thin 8- epress t `e same against l Since the strap 20 is prefc the part ofthe hangers to 5 oessive flexible straps.

1,5 strap having `a depressed central of the stil strap,

, adjacent end portion of sal sauramps. 4. A spring unit comprising a relatrvely y ull aw'a from the su rtin members gf the frime. To provllflldolatexgal .su port for the flexible members 24, a number ofsuitable links may be em loyed between sucese links may be made of stiil wire or the like, the ends of whichI are bent'back through suitable holes in the flexible straps 24. Thus each of the flexible straps is laterally supported .by all 0 the others so as toA prevent lateral yielding when a weight is placed the spring units.

e claim:

1. A spring unit comprising a stiff' metal portion and upwardly sloping end portions, a flexible strap extendlng horizontally above said still' on one or more of strap and having resilient end portions vcurved downwardly to lap under the ends a pair of hangers adapted to support the respective ends of the straps, each said hanger having a portion abuttin the under-turned end portion vof the ilexi le strap, means fastenin each hanger to the adjacent end portions osaid straps, and compression springs extending between the central portions of said straps.

2: A spring unit for a chair seat, comprising a stii' metal strap having a depressed a@ central portion and upwardly sloping end portions, a hanger at each end of said strap consisting of a piece of similar metal stoc having one end portion lap in'g below the strap and secured thereto, the other end of each said hanger being adapted to be secured to a chair frame, a iiexible spring metal strap of thinner stock horizontally disposed above said stiff strap, said thin strap having its end portions curved downwardly and secured face to face between the adjacent lapped end pori;

tions of the stift' strap and hanger, and a plurality of' compression springs each having its lower end secured to said stiff strap and its i upper end secured to said flexible strap.

3. A sup ort for' a chair seat, comprising a rectangulr frame, a plurality of spring units slung each said unit consisting of a-pair of hangers,

J each having one end secured to a side of said frame and the other end extending inwardly and downwardly,

posed horizontall said strap having its end u portions turned under and secured .against m5the upper faces of the respectivev hangers, a stiff strap having its end l.portions Secured upon respective end portions of said iexible strap, said stiff strap having a central por- 4tion s aced below tween said straps; and lateral means between adjacent units consisting o sti' wires linked at their ends to successive between two sides of said frame,

a flexible spring strap disi said flexible strap, and a` 6- plurahty of compression springs secured be- I -stif strap having a depressed central portion, upwardly extendin portions adjoining said central portion, an 'elevated end portions, and a relatively flexible strap horizontally extended above said central portion, the ends of said flexible strap beine turned under and secured respectively to the' upwardly extending portions of the still' strap.

5. A prlng unit comprising a relatively stiff strap having a depressed central portion, upwardly extending portions adjoining said central rtion, and elevated end portions, arelatively ilexible strap horizontally extended above said central portion, the ends of said llexible strap being turned under and secured respectively to the upwardly extending 'portions of the stili strap, and 'a compression sprin mounted between said central portion and said flexible stra 6. A spring unit comprising a relatively stiff strap having a depressed centralportion, upwardly extending portions adjoining said central portion, and elevated end portions, and a relatively flexible strap horizontally extended above saidI central portion, the ends of said flexible stra being turned under and secured respectively to the upwardly extendin .portions of the stiff strap, said stiff strap inc uding clamping portions bearing on substantial areas of the opposite faces of each end portion of said flexible strap.

spring unit comprising a relatively 'stiff strap consistin of three pieces permanently secured toget Ier by lap-joints to form a single length, said strap having a depressed central portion, upwardly extending. portions adjoining said central portion, and elevated end portions, said lap-joints being in said upwardly extending portions, and a comparatively iiexible strap horizontally extended above said stiff strap, the end portions of said exible strap being turned under and permanently secured respectively in said lapjoints.

In testimony whereof we have axed our 

